North Korea fired at least one ballistic missile Sunday morning — its first major weapons test since early June — as the Japan-based USS Ronald Reagan aircraft carrier visited South Korea for joint military drills just days before U.S. Vice President Kamala Harris visits the region.

Japanese Defense Minister Yasukazu Hamada said that at least one apparent ballistic missile had been fired, hitting a peak altitude of roughly 50 kilometers. Hamada said the weapon also appeared to fly on an irregular trajectory and that the ministry had estimated it would have traveled some 400 km if it had flown normally.

The defense chief said the missile was believed to have landed in an area of the Sea of Japan outside Japan's exclusive economic zone, which extends 200 nautical miles (370 km) from its coast.